Is NFS a security hole in the system or LAN? I was told by an engineer that NFS would not be something he recommend I install to use as a Linux file server. He said Samba was good but it is only for Linux boxes so I don't see why I have to hassle with Samba to simple transfer files back / fourth on a share.

Anyone recommend anything or is it safe to install NFS on a sever using it only as a file server on Debian?

I think you got it a little backwards. Samba allows file sharing with Windows and Mac OS X machines, but is not particularly secure, because it implements Windows SMB/NMB/CIFS protocol. NFS is generally only used on Linux/Unix machines, and has good security functionality, if you use it.

Depending on your clients, there are several choices. For file sharing among Linux machines, I prefer FUSE with FUSE-SSHFS. This implements a mounted filesystem, in userspace, over OpenSSH - one of the most carefully implemented and scrutinized secure applications.

I have never heard of FUSE and FURE-SSHFS but will look into them. I would just think NFS is a more popular and more documented install process.

Fuse and fuse-ssh are pretty trivial to use, since once the software is installed and the user authorized, everything is done by the user (not an admin):

To set it up, just do this once:

$ sudo apt-get install sshfs
$ sudo adduser yourlocalusername fuse
(log out and back in so that it recognizes you as a member of the group "fuse")

Mounting is as easy as:

$ sshfs -o reconnect yourremoteusername@remotehost:somedir/ mountpoint/

To unmount:

$ fusermount -u mountpoint